Took care of sister and daughter (6)
I believe the answer is:
nursed
'took care of' is the definition.
(I've seen this before)
'sister and daughter' is the wordplay.
'sister' becomes 'nurse' (I've seen this before).
'and' says to put letters next to each other.
'daughter' becomes 'd'.
'nurse'+'d'='NURSED'
(Other definitions for nursed that I've seen before include "Tended to the sick, cared for" , "given medical attention" , "Tended to while ill" , "Cherished" , "Sunder (anag)" .)